| New file |
|---|
| 0,0 → 1,85 |
|---|
| <html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" > |
| <head> |
| <title>Approximation of an arc with bezier</title> |
| <style type="text/css"> |
| @import "../../../dojo/resources/dojo.css"; |
| @import "../../../dijit/tests/css/dijitTests.css"; |
| </style> |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> |
| <!-- |
| The next line should include Microsoft's Silverligth.js, if you plan to use the silverlight backend |
| <script type="text/javascript" src="Silverlight.js"></script> |
| --> |
| <script type="text/javascript" src="../../../dojo/dojo.js" djConfig="isDebug: true"></script> |
| <script type="text/javascript" src="../_base.js"></script> |
| <script type="text/javascript" src="../shape.js"></script> |
| <script type="text/javascript" src="../path.js"></script> |
| <script type="text/javascript" src="../arc.js"></script> |
| <!--<script type="text/javascript" src="../vml.js"></script>--> |
| <!--<script type="text/javascript" src="../svg.js"></script>--> |
| <!--<script type="text/javascript" src="../canvas.js"></script>--> |
| <!--<script type="text/javascript" src="../silverlight.js"></script>--> |
| <script type="text/javascript"> |
| dojo.require("dojox.gfx"); |
| |
| makeShapes = function(){ |
| var surface = dojox.gfx.createSurface("test", 500, 300); |
| var g = surface.createGroup(); |
| |
| // create a reference ellipse |
| var rx = 200; |
| var ry = 100; |
| var startAngle = -30; |
| var arcAngle = -90; |
| var axisAngle = -30; |
| var e = g.createEllipse({rx: rx, ry: ry}).setStroke({}); |
| |
| // calculate a bezier |
| var alpha = dojox.gfx.matrix._degToRad(arcAngle) / 2; // half of our angle |
| var cosa = Math.cos(alpha); |
| var sina = Math.sin(alpha); |
| // start point |
| var p1 = {x: cosa, y: sina}; |
| // 1st control point |
| var p2 = {x: cosa + (4 / 3) * (1 - cosa), y: sina - (4 / 3) * cosa * (1 - cosa) / sina}; |
| // 2nd control point (symmetric to the 1st one) |
| var p3 = {x: p2.x, y: -p2.y}; |
| // end point (symmetric to the start point) |
| var p4 = {x: p1.x, y: -p1.y}; |
| |
| // rotate and scale poins as appropriate |
| var s = dojox.gfx.matrix.normalize([dojox.gfx.matrix.scale(e.shape.rx, e.shape.ry), dojox.gfx.matrix.rotateg(startAngle + arcAngle / 2)]); |
| p1 = dojox.gfx.matrix.multiplyPoint(s, p1); |
| p2 = dojox.gfx.matrix.multiplyPoint(s, p2); |
| p3 = dojox.gfx.matrix.multiplyPoint(s, p3); |
| p4 = dojox.gfx.matrix.multiplyPoint(s, p4); |
| // draw control trapezoid |
| var t = g.createPath().setStroke({color: "blue"}); |
| t.moveTo(p1.x, p1.y); |
| t.lineTo(p2.x, p2.y); |
| t.lineTo(p3.x, p3.y); |
| t.lineTo(p4.x, p4.y); |
| t.lineTo(p1.x, p1.y); |
| t.moveTo((p1.x + p4.x) / 2, (p1.y + p4.y) / 2); |
| t.lineTo((p2.x + p3.x) / 2, (p2.y + p3.y) / 2); |
| t.moveTo((p1.x + p2.x) / 2, (p1.y + p2.y) / 2); |
| t.lineTo((p3.x + p4.x) / 2, (p3.y + p4.y) / 2); |
| // draw a bezier |
| var b = g.createPath().setStroke({color: "red"}); |
| b.moveTo(p1.x, p1.y); |
| b.curveTo(p2.x, p2.y, p3.x, p3.y, p4.x, p4.y); |
| // move everything in a middle |
| g.setTransform([dojox.gfx.matrix.translate(250, 150), dojox.gfx.matrix.rotateg(axisAngle)]); |
| }; |
| |
| dojo.addOnLoad(makeShapes); |
| |
| </script> |
| </head> |
| <body> |
| <h1>Approximation of an arc with bezier</h1> |
| <!--<p><button onclick="makeShapes();">Make</button></p>--> |
| <div id="test" style="width: 500px; height: 300px;"></div> |
| <p>That's all Folks!</p> |
| </body> |
| </html> |